&GAS: INTERPOLATION


item

  The table item for which you wish to alter the interpolation
  method.

  ---------------------------------------------------------------
  Keyword                     Meaning
  ---------------------------------------------------------------
  ATTACHMENT-COEFFICIENT      Attachment coefficient of electrons
  DRIFT-VELOCITY              Electron drift velocity
  ION-MOBILITY                Mobility of ions
  LONGITUDINAL-DIFFUSION      Logitudinal diffusion of electrons
  LORENTZ-ANGLE               Lorentz angle of electrons
  TOWNSEND-COEFFICIENT        Townsend coefficient of electrons
  TRANSVERSE-DIFFUSION        Transverse diffusion of electrons
  ---------------------------------------------------------------

method

  The interpolation method to be used. The basic choice is between
  cubic splines and polynomial Newton interpolation.

  Spline interpolation leads to smooth looking graphs, but tends to
  oscillate making the method less suited for numerical calculations.
  Spline interpolation can not be used on the 2-dimensional gas
  tables that are produced by programs like Magboltz when a magnetic
  field is present.

  The order of polynomial interpolation must be between 1 and the
  smallest of the two numbers: 10 and number of table entries - 1.
  Orders larger than 2 are not recommended.

  Formats:

  INTERPOLATION item SPLINES
  INTERPOLATION item NEWTON order

  ---------------------------------------------------------------
  Method       Effect                                  Use
  ---------------------------------------------------------------
  SPLINES      Cubic spline interpolation              only 1-D
  NEWTON n     Polynomial interpolation of order n     1-D or 2-D
  LINEAR       Linear interpolation (= NEWTON 1)       1-D or 2-D
  QUADRATIC    Parabolic interpolation (=NEWTON 2)     1-D or 2-D
  CUBIC        Cubic interpolation (=NEWTON 3)         1-D or 2-D
  ---------------------------------------------------------------

Keyword index. Formatted on 10/11/98.